John Horel, Steven Lazarus, and Carol Ciliberti

NOAA Cooperative Institute for Regional Prediction

University of Utah

The Utah Arps Data Assimilation System (ADAS)

Based on the Oklahoma ARPS (Advanced Regional Prediction System) Data Assimilation System

• Developed by the Center for Analysis and Prediction of Storms (CAPS)

Project Goals:

• Obtain real-time, high resolution analyses over complex terrain




• Assist in local weather forecasting
  

Description of the Utah ADAS

 3-Dimensional mesoscale analysis system

 220x220 km domain

 2 km horizontal resolution

 Stretched vertical coordinate

 Run at one-hour intervals

 Analyses run in two parts

• temperature, relative humidity, pressure and wind analysis
  
  
• cloud analysis

Data Used in the Analyses

Main Analysis:

• RUC2 analysis used for initial background field

• Regression data replaces T, Td at first model level
• Surface obs from Utah mesonet
• NWS rawinsonde at 0 and 12 UTC
• NWS WSR-88D velocity and reflectivity data

Cloud Analysis

• 3-D background field from ADAS RH analysis
• Option to use METAR data
• Visible and Infrared satellite imagery
• Radar reflectivities

ADAS Features

Bratseth Interpolation Scheme

• Successive correction technique
• Accounts for background-to-observation error
• Generally insensitive to observation density

Automated Quality Control

• 2-Dimensional scheme

New Vertical Weighting Added to Analysis

Future Goals

Incorporate Additional Data Sources

• Satellite sounder data
• Dugway Proving Grounds wind profiler data
• ACARS data
• FAA radar data

Implement Linear Regression Q-C Flags

Experiment with domain size and resolution

Use ADAS to initialize ARPS

• short term, high resolution forecasts
  
  
  

Products Available

Utah Mesonet Web Page

http://www.met.utah.edu/jhorel/mesonet/data.html

Utah ADAS Information http://www.met.utah.edu/jhorel/html/adas/info/information.html

Conference Papers:

Application of a Local Data Analysis System in Highly Variable Terrain.